/*
 * Copyright (C) 2018 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

import java.util.Spliterator;
import java.util.function.Consumer;

import org.checkerframework.checker.nullness.qual.Nullable;

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
abstract class IndexedImmutableSet<E> extends ImmutableSet.CachingAsList<E>
{
    abstract E get(int index);

    @Override
    public UnmodifiableIterator<E> iterator()
    {
        return asList().iterator();
    }

    @Override
    public Spliterator<E> spliterator()
    {
        return CollectSpliterators.indexed(size(), SPLITERATOR_CHARACTERISTICS, this::get);
    }

    @Override
    public void forEach(Consumer<? super E> consumer)
    {
        checkNotNull(consumer);
        int n = size();
        for (int i = 0; i < n; i++)
        {
            consumer.accept(get(i));
        }
    }

    @Override
    @GwtIncompatible
    int copyIntoArray(@Nullable Object[] dst, int offset)
    {
        return asList().copyIntoArray(dst, offset);
    }

    @Override
    ImmutableList<E> createAsList()
    {
        return new ImmutableAsList<E>()
        {
            @Override
            public E get(int index)
            {
                return IndexedImmutableSet.this.get(index);
            }

            @Override
            boolean isPartialView()
            {
                return IndexedImmutableSet.this.isPartialView();
            }

            @Override
            public int size()
            {
                return IndexedImmutableSet.this.size();
            }

            @Override
            ImmutableCollection<E> delegateCollection()
            {
                return IndexedImmutableSet.this;
            }
        };
    }
}
